In recent years, water having a higher dissolved gas content than general water has been produced. By way of example, oxygen (gas) water having a high dissolved oxygen content has been mainly used for purifying wastewater from a stock farm or supplying oxygen (gas) to fish in a fish farm. If an animal or a human drinks the oxygen water, the oxygen water is quickly absorbed into the body and activates metabolism and makes the body resistant to various insect pests and diseases. Therefore, such oxygen water has been often used not only in stock farms but also in water purifiers of family homes or companies. Further, as for plants, oxygen water improves the soil environment and directly supplies oxygen to leaves or roots, and thus, helps the plants grow stronger and makes the plants resistant to insect pests and diseases, resulting in an increase in production. For the above-described reasons, various methods and apparatuses have been provided in order to produce oxygen (gas, bubble) water. Conventionally, the methods and apparatuses for producing gas water using a motor to mix water at a high speed while increasing the dissolved gas content. However, according to such a method, it is difficult to obtain a desirable dissolved gas content in a short time and also difficult to generate microbubbles. Further, there has been provided a method for producing oxygen (gas) water by electrolysis or freezing. In this case, the system is very expensive, and mixed oxygen (gas) is present in the form of bubbles in water. Therefore, the dissolved oxygen content rapidly decreases depending on time and a size of a bubble cannot be controlled. Furthermore, according to a method for producing oxygen (gas) water by supplying micro-air-bubbles, it is possible to produce high-concentration oxygen (gas) water, but it is necessary to continuously generate and supply nanobubbles under a high pressure condition in order to supply nanobubbles. Also, in this case, a considerable amount of oxygen (gas) is present in the form of bubbles in water and the dissolved oxygen content rapidly decreases depending on time.
A serum is a composite product in which various materials are mixed, and is used as an additive to a basic cell culture medium in a cell incubation room, and the serum for cell culture includes growth factors, hormones, components that stimulates cells, etc. and is variously used according to the kind of a cell. In general, however, fetal bovine serum (FBS) is the most widely used serum. The FBS is a serum which is isolated from the blood of a cow during pregnancy, and in particular, is used as a raw material in developing vaccines, protein medical supplies, and therapeutic antibodies of which technology development is being accelerated around the world for recent several years, as well as in culturing animal cells, which is a basic step in biotechnology related experiments. However, recently, the supply of the FBS has been restricted following the outbreak of bovine spongiform encephalopathy, and the price thereof has risen sharply. Further, a target product can be infected with bovine spongiform encephalopathy, and thus, the safety thereof cannot be sufficiently guaranteed. The Korean FBS market is worth about 20 billion won, and the world market for FBS is worth about 2 trillion won. American FBS accounts for about 85% and Australian and New Zealand FBS accounts for about 15%. Korean FBS has not been produced or has not been commercialized on sale. Accordingly, once the FBS import is banned, there are few available countermeasures. Therefore, the need for development of other serums as alternatives to the FBS or components of a culture medium has been greatly increased. Korean Patent No. 10-0394430 describes a method for culturing a human cell comprising a human serum in a medium used for culturing a human cell. However, according to the above-described patent, the medium can be infected with human viruses such as AIDS and the supply thereof is restricted. Further, it is not very effective in culturing other animal cells, and even when culturing a human cell, it is much less effective than a medium using FBS. Therefore, it cannot be a complete alternative to FBS. It may help a slight reduction in the use of FBS, but its economical efficiency is very low. Therefore, development of other serums as alternatives to the FBS or other components of a culture medium which can reduce the use of FBS and also promote cell growth has been demanded. In this regard, the use of high-priced FBS has been reduced by using nanobubble water as a component for cell culture.
Meanwhile, fossil fuels have been mainly used as energy sources on earth, and such fossil fuels are limited in their respective reserves. Therefore, they need to be efficiently used. Middle Eastern crude oil prices have been continuously increased every year. According to the IEA (International Energy Agency) 2010 data, Middle Eastern crude oil prices are expected to reach about $243.8/BL in 2035. The average oil consumption per day in 2010 was about 80.740 million BL, and an increase in oil consumption and an increase in oil prices have emerged as a major issue. Attention to development of a next-generation fuel has been demanded. Although studies for developing fuel cells or hydrogen fuels as alternative energy sources have been carried out, development of a high-efficiency energy source is needed in order to suppress oil consumption. Korean Patent No. 10-1071461 relates to a microbubble generation apparatus, and describes a microbubble generation apparatus that converts a mixed oil including water and fuel into an emulsion state by stirring. However, according to the above-described method, the mixed oil converted into an emulsion state may be unstable in a certain period of time, and the water and the fuel may separate. In order to solve this problem, development of a high-efficiency fuel which is stable and in which separation does not occur is demanded.